The isolation and characterization of polysaccharides from longan pulp (original) (raw)
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Banana is one of the most important fruits over the world. The chemical composition is critical for the organoleptic properties and health benefits. As one of the leading bioactive components in banana pulp, the polysaccharides may contribute to the beneficial health effects. However, their precise structure information remains unknown. A leading acidic polysaccharide (ABPP) of banana pulp was purified and identified by nuclear magnetic resonnance spectroscopy (NMR) and gas chromatography-mass spec-trometry (GC–MS). →4-d-GalpA-1→ and →4-d-GalpAMe-1→ constituted the backbone. No branch chains were detected. The molecular weight was determined to be 8.9 kDa by gel permeation chromatography , which was smaller than previously reported fruit-derived polygalacturonic acids. The precise structure was identified as below. Digestion by enzyme would lead to production of oligogalacturonic acids and quick accumulation of 5000–7000 Da fraction.
Physico-chemical characterization of alkaline soluble polysaccharides from sugar beet pulp
Food Hydrocolloids, 2009
We studied the global (i.e. overall) structure of microwave-assisted alkaline soluble polysaccharides (ASP) isolated from fresh sugar beet pulp. The objective was to minimize the disassembly and possibly the degradation of these polysaccharides during extraction. Prior to ASP microwave-assisted extraction (MAE), pectin was removed and isolated by MAE. Two sub fractions, ASP I and ASP II were isolated. ASP I had about the same ratio of anhydrogalacturonate (AGA) to neutral sugar (NS) by percentage weight (%wt) whereas ASP II had about twice as much AGA to NS by %wt. Unlike the sugar beet pectin isolated, the degree of methyl esterification of AGA in both ASP fractions was very low. Arabinose was the most abundant neutral sugar followed by either rhamnose or galactose. For optimum sample 10/100/30, High Performance Size Exclusion Chromatography with molar mass and viscometric detection revealed that both ASP fractions are about 100,000 Da in M w and about 10 and 16 nm in Rg z , respectively. ASP I and ASP II had weight average intrinsic viscosities of 0.31 and 0.33 dL/g respectively and their Mark-Houwink exponents indicated that they are relatively compact in shape. Molar Mass distributions of ASP appeared to be bimodal in shape. Atomic Force Microscopy (AFM) images of ASP I revealed a bimodal distribution of small and large compact asymmetric subunits when a 0.1 mg/mL air dried, aqueous solution was deposited on freshly cleaved mica and imaged. When the solution concentration was 25 mg/mL in ASP I, the subunits appeared to aggregate into skeletal structures whereas ASP II only formed compact asymmetric structures. Unlike AFM images of sugar beet pectin previously imaged, neither ASP I nor ASP II formed network structures at higher concentrations. Both ASP I and II were found to emulsify orange oil.
2015
The cubiu (Solanum sessiliflorum Dunal, Solanaceae) is a native fruit from the Amazon. The pulp has characteristic acid flavor and is used by the local population in the preparation of jams and sauces, and is used in traditional medicine to control diabetes, cholesterol and uric acid. In this work, pulp and peel of cubiu were lyophilized, ground and treated with ethanol. Both materials were subjected to sequential extractions with DMSO, water, EDTA, citric acid and NaOH. Extractions with DMSO solubilized mainly starch; aqueous, with EDTA and acid ones, especially pectins; and alkaline, hemicelluloses. The higher yielding fractions were extracted from the pulp with 90% DMSO (DMSO-P fraction, 9.6% yield) and water at 100°C (HW-P fraction, 4.8% yield) and from peel with water at 100°C (HW-S fraction, 9.6% yield). Chemical and spectroscopic analyzes showed that the HW-S fraction is mainly composed of a homogalacturonan high degree of methyl-esterification (AU = 79.0%; DM = 56.9%), together with a small proportion of type II arabinogalactan. Tests were performed for pectin extraction from the peel, in order to obtain pectins with high yield and uronic acid content. The extractions were carried out at 100°C using citric and nitric acids. Nitric acid provided pectins with more uronic acid content, while the yield was not affected by the type of acid. Then, extractions were performed with nitric acid at the same temperature, varying pH (1.0, 1.5 and 2.0) and time (2 or 4 hours) and the best experimental conditions were pH 1.5 and 2h, providing N15t2 fraction with a yield of ~14% and uronic acid content of 79%. Spectroscopic analysis showed that the pectin has a high degree of methyl-esterification (62%). The gel forming ability of this fraction was tested. Gels were prepared at a concentration of 3% (w/w) N15t2, and 60% (w/w) sucrose, at pH 1.5; 2.0; 2.5 and 3.0. Rheological analyzes have shown that gelation occurs only at pH<3.0, and that the gel strength increases as the pH decreases, but at pH below 2.0, the increase in acidity of the medium does not quite affect the strength the gel. The fruit pulp was also evaluated as to their composition and composition of volatile. The result proved high fiber (27.0% based on the weight of dry pulp) and minerals: magnesium (172.7mg / 100 g), phosphorus (293.4mg / 100g) and potassium (2998.7mg / 100g). Seven volatile components were identified in lyophilized pulp, and butylated hydroxytoluene (BHT) was the major compound (46.8% total volatiles), followed by ethyldodecanoate (18.7%) and E-βfarnesene (10, 0%).
Cellulose, 2013
Three different commercial b-1,4-endoxylanase preparations were used to hydrolyze bleached kraft pulp. Xylo-oligosaccharides in the produced filtrates were separated and quantified using both high performance liquid chromatography (HPLC) and capillary electrophoresis (CE). All the determinations were performed without sample derivatization. The analytical methods were used to highlight the differences between the enzymes behaviour in terms of hydrolysates, but also to estimate the productivity of xylo-oligosaccharides from kraft pulp when the bleached material would be used in biorefining industry. The research showed that the glycosyl hydrolase family 10 enzyme produced by Aspergillus oryzae released xylobiose and xylotriose from the pulp material. The major oligosaccharides released by the family 11 enzyme produced by Bacillus sp. were xylotriose, xylobiose and xylotetraose. On the contrary, another family 11 enzyme produced by A. oryzae produced also xylose. The HPLC results agreed well with the xylose concentrations obtained after acid hydrolysis. The CE data showed the same trend, but much lower concentrations were identified than with HPLC. At the same time the HPLC method was able to separate only small oligosaccharides, whereas CE could be used for separation of all the xylo-oligosaccharides from xylobiose to xylohexaose. The highest xylo-oligosaccharide yield was achieved with Shearzyme at pH 5 corresponding to 22 % of total xylan from bleached birch kraft pulp. Keywords Bleached kraft pulp Á Enzymatic hydrolysis Á Oligosaccharides Á Xylan Á Xylanases
Sources, Extraction and Biomedical Properties of Polysaccharides
Foods, 2019
In the recent era, bioactive compounds from plants have received great attention because of their vital health-related activities, such as antimicrobial activity, antioxidant activity, anticoagulant activity, anti-diabetic activity, UV protection, antiviral activity, hypoglycemia, etc. Previous studies have already shown that polysaccharides found in plants are not likely to be toxic. Based on these inspirational comments, most research focused on the isolation, identification, and bioactivities of polysaccharides. A large number of biologically active polysaccharides have been isolated with varying structural and biological activities. In this review, a comprehensive summary is provided of the recent developments in the physical and chemical properties as well as biological activities of polysaccharides from a number of important natural sources, such as wheat bran, orange peel, barely, fungi, algae, lichen, etc. This review also focused on biomedical applications of polysaccharide...
Carbohydrate Polymers, 2013
We have solubilized and separated polysaccharides from sugar beet pulp (SBP) into three fractions with steam assisted flash extraction (SAFE). For pectin, recovery ranged from 8 to 14%, degree of methy-esterification 66-73%, crude protein 1.3-1.7%, M w 262-318 kDa, Á w 0.22-0.23 dL/g, Rg z 36-39 nm and Rh z 41-42 nm. For alkaline soluble polysaccharides, (ASP I) recovery ranged from 4.0 to 6.5%, crude protein 1.2-4.8%, weight average molar mass (M w ) 66-68 kDa, weight average intrinsic viscosity (Á w ) 0.27-0.30 dL/g, z-average radius of gyration (Rg z ) 25-29 nm and z-average hydrated radius (Rh z ) 10-11 nm. ASP II recovery ranged from 2.0 to 8.6%, crude protein 1.2-4.8%, M w 299-339 kDa, Á w 0.22-0.33 dL/g, Rg z 33-34 nm and Rh z 30-34 nm. Recovery of the residue mainly cellulose, ranged from 20.3 to 22.3%. The cellulose in this fraction was converted to carboxymethyl cellulose (CMC). The CMC fraction contained 0.33-0.43 crude protein and had an M w ranging from 127 to 263 kDa, Á w 3.6-8.0 dL/g, Rg z 35-45 nm and Rh z 27-40 nm.
Industrial Crops and Products, 2009
Acid hydrolysis Enzymatic hydrolysis GC-FID GC-MS HPAEC-PAD HPAEC-Borate a b s t r a c t Acid hydrolysis, acid methanolysis, and enzymatic hydrolysis were compared for depolymerization of five different plant materials containing uronic acids. The analyzed plant materials were oat spelt, wheat straw, spruce thermomechanical pulp, aspen stemwood, and totally chlorine-free (TCF) bleached hardwood kraft pulp. Furthermore, GC (using both HP-1 and HP-5 capillary columns and FID and MSD detectors), HPAEC-PAD, and HPAEC-Borate techniques were compared for subsequent analysis of the released monosaccharides.